Starting mechanism for internal combustion engines



Feb. 29, 1944. M. L. LOCKHART 2,343,195

STARTING MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed Dec. 24. 1941 45 L J c fzyezzfoz g? Zia/2% Z. Zariarf Patented Feb. 29, 1944 UNITED STATES PATENT OFFICE STARTING MECHANISM FOR INTERNAL COMBUSTION ENGINES Marshall L. Lockhart, Ossining, N. Y. Application December 24, 1941, Serial No. 424,264

20 Claims.

My present invention relates to a simple starting mechanism for an internal combustion engine which utilizes parts of the engine itself and the regular fuel for the engine to accomplish the starting operation without the use of auxiliary devices, the starting mechanism being thereby particularly adaptable for the starting of aeroplane engines wherein thesaving of Weight is a substantial factor.

'One object of the invention is to provide starting mechanism which is of simple and durable construction and which may be inexpensively manufactured and installed.

A further object is to provide starting mechanism which is explosion operated and utilizes one of the pistons and cylinders of the engine as a means to compress air and into which fuel is injected so that an explosive mixture is thereby provided therein, the starting mechanism thereupon furnishinga spark for said cylinder which acts upon the piston therein and rotates the crank shaft in the proper direction for starting the engine.

Another object is to provide starting mechanism which may use the fuel injector system of an internal combustion engine where such is provided in place of a carbureter or in which fuel injectors, in addition to the carburetor, may be used for starting purposes.

Still another object is to provide starting mechanism which utilizes the impulse mechanism of an impulse magneto where the engine is so equipped for the purpose of furnishing a startim: spark, which spark may otherwise be furnishe'd by an ordinary vibrator type spark coll if the engine lacks an impulse magneto.

With these and other objects in view, my invention consists in the combination, construct on and arrangement of the various parts of my device and in the practice of my method whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompany- "in'g drawing, in which:

Figure 1 is a diagrammatic view of an internal combustion engine, together with portions of its fuel injector system and the impulse magneto of the engine;

Figure 2 is a diagrammatic view showing various positions of the particular piston and cylinder which is utilized for the starting operation, together with various angles through which the ignition mechanism operates for normal and for starting operations to give a comparison of such positions in relation to each other;

Figure 3 is a diagrammatic view of a portion of Figure 1 showing a modified construction in which a spark coil and a separate distributor for starting-purposes is shown; and

Figure 4 is a sectional view on the line 4-4 of Figure 3 showing a special automatic switch used in connection with the system shown in Figure 3.

On the accompanying drawing I have shown my starting mechanism applied to an internal combustion engine such as a radial aeroplane engine, the cylinders of which are indicated at C C C C and C A piston P is provided in the cylinder C and similar pistons are provided in the other cylinders. The cylinder C has a spark plug S and the other cylinders have similar spark plugs.

The crank shaft of the engine is indicated at It, the crank thereof being shown at l2, and the crank pin at 13. A master connecting rod I4 is journaled on the crank pin l3 and has secondary connecting rods l5 pivoted to the master connecting rod in the usual manner. The engine thus far described, of course, forms no part of my present invention, and is shown merely by way of illustration.

The internal combustion engine also described may have an impulse type magneto, shown at it. The magneto I6 includes a distributor ll from which wires W W W W and W extend to the spark plugs S S S S and S respectively. Only two of the wires (W and W have been shown completely in order to eliminate confusion on the drawing. The distributor H includes a drive shaft IE on which a distributor arm I9 is mounted in the usual manner for timing cooperation with the wires W W W W and W A four-cycle engine is illustrated, and. accordingly, 2:1 reducing gears 20 and El are provided for operating the magneto and properly timing the distributor IT.

The magneto I6 is of the impulse type, and the impulse mechanism is operated as by a lever 22. The lever 22 is for the purpose of winding a spring on the magneto shaft which, at the proper time, (when a spark is necessary at one of the distributor points) releases the armature so that the spring gives it a quick rotational flip to produce a relatively hot spark for starting purposes. Since the magneto It forms no part of my present in vention I shall not go further into detail with respect to the description of the impulse mechanism 22.

I have shown an engine having a fuel injector 23 for each of the cylinders C, C C C and C These injectors are used normally in place of a carburetor. Where the engine is equipped with a carburetor, then I may provide the injectors 23 in addition thereto. The injectors 23 are supplied with fuel, as through a pipe line 24, from a fuel tank 25. Where the injectors 23 are part of the engine, they are operated by a suitable cam (not shown), driven from the timing shaft l8. For the'purpose of my starting apparatus I provide an addi ional cam 23, which may be termed an injector cam. The cam 23 has a lobe 21 for each of the fuel injectors 23, and may be suitably journaled around the crank shaft II), but is not driven therefrom. Instead, the cam 25 is normally held against a stop 28 by a biasing means, such as a spring 29, and for operating the cam a link 30 is provided.

Secured to the crank shaft I0 is a starting cam 3|. The starting cam 3| has a lobe or notch for each cylinder, which notches are indicated at N N N3, N and N respectively. The starting cam 3| is adapted to be rotated in a backward direction or a reverse direction relative to the normal rotation of the crank shaft I l), and for this purpose I provide a starting pedal 32. The pedal 32 is connected by a link 33 with a pawl lever 34 pivoted to oscillate aroundthe crankshaft Ill. The pawl lever 34 carries a pawl 35 which is normally held in a position free of the starting cam 3| by a tail-piece 3B of the pawl engaging a stationary stop pin. 31. This is the normal or inoperative position of the starting pedal 32, and such position is automatically assumed due to the bias of a spring 38.

The pawl lever 34 has an extension 33 adapted at the proper time to engage the link 30 for operating the injector cam 26. The distributor i1 is also operated by the starting pedal 32 through the medium of a push rod 42 and acam 4U having a lobe 4|. The rod 42 is connected to an 'adjusting arm 43 of the distributor H. The rod 42 is adapted to swing the distributor I! through angle Y from normal top dead center firing position to a greatly retarded firing position indicated at 43*. During normal operation of the engine the distributor may be advanced to any position in angle X by the usual timing governing mechanism of the engine (not here illustrated).

I also provide means to operate the impulse starter in the form of a push rod 45 extending from the lever 22 to a cam 45 and its lobe 45 of the starting lever 32. A stationary stop 45 is provided for the starting lever at the inward end of its stroke, the stop pin 31 acting to limit the return movement of the pedal.

In Figure 3 I show a modified construction foran internal combustion engine that is not provided with an impulse magneto. In this case an auxiliary distributor Il or one in addition to the one used for the regular ignition mechanism of the engine may be provided. This distributor is permanently set'at a greatly retarded position with respect to the regular ignition system. For furnishing a spark through the distributor ll perhaps the simplest mechanism is an ordinary jump spark coil SC, the primary of which is indicated at 41 and the secondary at 48. A battery 49 is provided for the purpose of energizing the spark coil SC and a switch 5|] is provided for automatically controlling the spark coil.

The switch 50 must be of some special construction such as shown in Figure 4 to avoid establishing a circuit when the starting pedal 32 is pushed'in toward starting position, with the switch operating to establish the circuit through th spark coil when the lever 32 returns. By way of illustration, a switch lever 5| is plvotally mounted in the switch 50 and switch contacts are 6 shown at 54 and 55, 54 being a stationary spring mounted contact and 55 a movable contact mounted on the switch lever 5 I Rractical operation In the operation of my starting mechanism for internal combustion engines I will first describe the theory of operation and then specifically describe how the starting mechanism operates.

Referring to Figure 2, a circle 56 illustrates the path of rotation of the crank pin l3. In the particular position of the pistons illustrated in Figure 1, cylinder (J and piston P are the particular ones involved in the starting operation. P has passed top dead center, indicated at TDC 20 in Figure 3, and nearly reached bottom dead center, indicated at BDC, as shown by solid lines. The ignition timing (in either a battery operated type of ignition or a magneto type of ignition) may vary through an arc of the circle 56, indi- 25 cated as angle X. There are two semi-circular arrows, labeled Firing stroke and Exhaust stroke. Theseapply to the cylinder C If, now, the crank pin 13 is moved from its fullline position to the dotted position illustrated as 30 l3 (this being in the reverse direction with relation to the normal direction of rotation of the engine) then the air and any spent gases in the cylinder C will be compressed up to a point approximating half the usual compression for the 35 cylinder. When the piston has been thus moved it is obvious that the injection of fuel into the cylinder C and the supplying of a spark for igniting the same will cause an explosion to drive the piston P downwardly in the cylinder C thus rotating the crank shaft l0 sufiiciently to cause the engine to start and keep running on the regular ignition circuit. In actual tests I have found that the crank shaft is rotated by this starting arrangement one and one-half to two revolutions without the regular ignition mechanism in the circuit.

It is now obvious that if fuel is injected into each of the five cylinders and the regular ignition circuit is closed, each of the cylinders will be primed so that the initial rotation given by the piston P in the starting operation will be more than sufiicient to start'the engine.

Referring now to the operation of my starting mechanism for accomplishing the results described in connection'with Figure 2, when it is desirable to start the engine, the regular ignition circuit is turned on and the starting pedal 32 then depressed. Depression of the pedal 32 accomplishes three major operation, as follows: (1) the'starting cam 3| is rotated approximately a quarter of a turn for rotating the crank shaft H! in a backward direction of rotation, as, for instance, movement of the crank pin l3 in Figure 2 from the full-line position to the dotted line position of l3 (2) The injectors 23 are each operated. for injecting'a priming charge of fuel into each cylinder of the engine; and (3) The magneto I6 is operated for furnishing a spark to the cylinder in which compression desirably 0ccurs, the illustrated instance of Figure 2 being the cylinder C With further reference to the details of operation, as the pedal 32 is depressed to finally assume a position'against the stop 45, as shown by ":a dotted lines in Figure 1, the pawl lever 34 is rothat the spark coil :30 is energized and the proper tated clockwise, which first permits the tail-piece 36 to leave the stop 3''! as the pawl lever 34 leaves the stop, and the pawl 35 under its spring-bias to drop into position for engaging the proper notch in the starting cam 31. In this instance it would be the notch N Adjacent the end of the inward stroke the extension 39 of the lever 34 engages the rod (ii) to rotate the injector cam 26 away from the stop 28 against the bias of the spring 29 so that the five lobes 2'! operate the five plungers of the injectors '23. Thus each cylinder is primed with a charge, of fuel for starting purposes, and cylinder C now contains a mixture of compressed air and possibly some exhaust gases, together with a charge of fuel which forms a mixture sufliciently combustible to initiate starting operation when it is ignited by the spark plug 53 he the pedal 32 is depressed the first action it has on the magneto It is to retard the distributor through angle Y so that it then assumes its dotted position, and the timing period for the ignition system will be that represented by the angle Y in Figure 2 instead of the normal angle indicated at X. This retarding operation occurs during the first inch or so of movement of the pedal 32, after which there 'is no further retardation of the distributor l1 due to the rod 42 riding on the topof the lobe 4 I The initial depressing movement of the starting pedal 32 will also permit the impulse lever 22 to move from the full-line position of Figure 1 to the dotted line position. Accordingly, on the return stroke of the-pedal Mend before the distributor arm 43 has started to move back from :1;

the position 53 toward its solid line position, the impulse starter lever '22 will be moved to the fullline position by its return spring causing the rod 45 to follow down the lobe 45 of the'cam 45.

This results in a surge of high tension current passing through the distributor contact l9 to the contact connected with the spark plug Wire W During the remaining return movement of the starting pedal 32 the distributor arm 43 will be moved back to the full-line position for normal operation of the ignition system to keep the engine running after the first starting explosion Occurs in the cylinder C Although I have described operation in connection with the cylinder C it is obvious, since the starting cam Si is provided with a notch for each cylinder, that any one of the cylinders may be the starting cylinder, depending on which one has its crank pin on the firing stroke anywhere between a mid-point, indicated at 5'! in Figure 2, and bottom dead center BDC.

The operation of Figure 3 is substantially similar to the operation of Figure l, with the following noted diiferences:

As the starting pedal 32 is depressed in the direction of the dotted line arrow, it engages the switch lever 51, as shown by dotted lines in Fig- .ure 4, to swing it clockwise so that the contacts 54 and 55 do not engage. The distributor I"! (being auxiliary to the regular ignition distributor and being already in a retarded position) need not be adjustable. During the return stroke of the starting pedal 32 in the direction of the dash line arrow (after the cylinders have been primed and the crank shaft rotated backwardsto the proper point) the pedal 32 engages the other side of the switch lever 5|, as shown by dash lines, thereby tilting it in a counterclockwise direction. This causes the contact 55 to engage with the contact 54 momentarily, so

cylinder (in this case, .0 again) is on so that as soon as compression occurs in the next cylinder (C and successively in cylinders C C and C. (in the .case of a four-cycle engine) the engine will be under way, receiving fuel from the regular injection system or carburetor as the injected starting charges will now be expended.

From the foregoing description it will be obvious that I have provided a starting system which, with the addition of a few mechanical elements to an ordinary internal combustion engine, adapts it for self-starting, using the fuel that is provided for running the engine. Either the ignition system can be adjusted for starting purposes, as in the case of Figure 1, or a separate starting ignition system can be provided, as found suitable. Likewise, either the injector system of the engine may be used for starting purposes, or, as where a carburetor is used for running the engine, a separate injecting or priming system may be used.

Although I have shown and described my starting mechanism in connection with a four-cycle engine, it may obviously be adapted for two-cycle engines as well, and for any type of internal combustion engine, either reciprocating or rotary type, where compression may be .efiected by a foot pedal or the like in at least one of thecombustion spaces, and fuel may then be injected into it and fired.

Having described two specific embodiments of my invention together with the operation thereof, 1 desire it to be understood that these forms are selected merely for the purpose of facilitating disclosure of the invention rather than for the purpose of limiting the number of forms which it may assume. It is to be further understood that various modifications, adaptations and alterations may be applied to the specific forms disclosed to meet the requirements of practice without in any manner departing from the spirit and scope of the present invention except as set forth in the claims appended hereto.

I claim as my invention:

1. Starting mechanism for a multiple cylinder internal combustion engine comprising means to rotate the engine backwards from stopped position to efiect compression of air in one of the cylinders thereof, the piston of which passed the normal firing point just previously to stoppage of the engine, means for injecting fuel into said cylinder, and means for producing a spark in said cylinder for firing the mixture of fuel and compressed air therein.

2. Starting mechanism for an internal combustion engine comprising means to rotate the crank shaft of the engine when stopped backwards to efiect compression of air in a cylinder that has been fired before the engine is stopped. and means for injecting fuel into said cylinder and producing a spark therein to explode the mixture of fuel and compressed air therein.

3. In starting mechanism for an internal oombustion engine, means to rotate the engine backwards from a standstill position to effect compression of air in a cylinder, the piston of which passed top dead center previous to the engine assuming a standstill position, means for injecting fuel into the cylinders of the engine, and means for producing a spark in said cylinder for firing the mixture of fuel and compressed air therein to thereby rotate the engine in its normal direction.

4. In starting mechanism for an internal com- 'bustion engine having. a fuel injector for the cylinders thereof, means to rotate the engine backwards froma standstill position to effect compression of air in a cylinder thereof, the piston of which has passed top dead center on its firing stroke before the engine is stopped following a previous operation, means for operatin said fuel injector, and means for producing a spark in said cylinder for firing the mixture of fuel and compressed air therein.

5. In starting mechanism for a multi-cylinder internal combustion engine having a fuel injector for its cylinders, means to rotate the crank shaft of the engine backwards after stoppage thereof to effect compression of air in at least one of said cylinders, means for operating said fuel injector, and means for producing a spark in said one of said cylinders to start the engine in its normal forward direction of rotation.

6. In starting mechanism for an internal combustion engine, an injector, means to operate said injector and'to rotate the enginebackwards after stoppage thereof to effect compression of air in one of the cylinders thereof, and means for producing a spark in said cylinder for firing the 1 mixture of injected fuel and compressed air therein and thereby again starting said engine in only a forward direction.

- '7. In starting mechanism for an internal combustion engine having a compression chamber, an injector for injecting fuel into said chamber, means to operate said injector and to rotate the engine backwards from a standstill position to effect compression of air in said compression chamber, said means operating said injector, and

means for producing. a spark in said chamber for firing the mixture of injected fuel and compressed air thereinand thereby rotate the engine in its normal direction. l

8. Starting mechanism for an internal combustion engine having adjustably timed ignition mechanism comprising means to rotate the drive shaft of said engine from a stopped positioned and in a reverse direction relative to normal to thereby effect compression'of air in a combustion chamber which has been fired, means for. injecting fuel into said chamber, and means for retarding said ignition mechanism and causing it to operate to thereby fire the mixture of fuel and compressed air in said chamber and effect rotation of the engine in said normal direction.

9. Starting mechanism for a multi-cylinder internal combustion engine having ignition mechanism comprising means to rotate the engine in a reverse direction relative to normal,

and from a stationary position to thereby effect compression of air in a cylinder which has been previously fired before the engine stopped,-means for injecting fuel into all-cylinders of the engine, means for retarding said ignition mechanism of the engine and causing it to operate once to thereby fire the mixture of fuel and compressed air .in said cylinder to effect forward starting rotation of the engine, and; means for thereafter advancing said ignition mechanism to normal running position.

10. Starting mechanism for an internal com bustion engine having an impulse magneto provided with a distributor comprising means to rotate the engine from a stationary position and in a backward direction relative to its normal direction of rotation to thereby effect compression of air in one of the cylinders of the engine,

means for injecting fuel into all of the cylinders, means for operating said impulse magneto thereafter for firing the mixture of fuel and compressed air in said one cylinder, and means for retarding said distributor to effect firing of said mixture of fuel and compressed air in said cylinhas passed the normal firing point previouslyto stopping of the engine, means for injecting fuel into the engine, and means for operating said impulse magneto thereafter for firing the mixture of fuel and compressed air in said cylinder to start the engine rotating in the normal direction.

12. Starting mechanism for an internal combustion engine comprising means to rotate the engine backwards after the same has stoppedrotation, to effect compression of air in a predetermined cylinder of the engine, means for injecting fuel into the cylinders of the engine, a spark coil, and means for operating said spark coil for firing the mixture of fuel and compressed air in said predetermined cylinder and for timing the spark to produce such firing when the piston of said cylinder is moved upwardly in the cylinder to a point intermediate top and bottom dead centers to thereby start the engine in a forward direction.

13. Starting mechanism for an internal'combustion engine comprising means to rotate the engine backwards after the same has stopped to effect compression of air in a cylinder thereof, means for injecting fuel into said cylinder, a spark coil, and means for operating said spark coil for firing the mixture of fuel and compressed air in said cylinder at the proper time to rotate said engine in a forward direction only.

14. Starting mechanism for an internal combustion engine comprising means to rotate the engine backwards from a standstill position to effect compression of air in a cylinder, the piston of which has passed top dead center on its firing stroke previous to assuming said standstill position, the degree of backward rotation being only from adjacent bottom dead center of said piston to a point substantially midway between bottom dead center and top dead center, a distributor timed to fire the mixture of fuel and compressed air in said cylinder after the cylinder has been moved to said point to thereby start the engine in a forward direction, and means for furnishing a spark for said cylinder through said distributor.

15. Starting mechanism for an internal combustion engine comprising means to rotate the engine backwards after stoppage thereof to effect compression of air in one of the cylinders thereof, the degree of backward rotation being only from adjacent bottom dead center to a point between bottom dead center and top dead center of the firing stroke of said piston, a distributor timed to fire the mixture of fuel and compressed air in said cylinder after the cylinder has been moved to said point, and means for furnishing an ignition spark for said cylinder through said distributor to effect only forward rotation of said engine.

16. Starting mechanism for an internal combustion engine comprising means, after the engine has stopped, to rotate the engine backwards, a

spark coil, a distributor set at a greatly retarded position, means for injecting fuel into the cylinders of the engine, and means for causing operation of said spark coil through said distributor at said retarded position to fire the spark plug of one of the engine cylinders wherein air has been compressed to effect only a forward direction of rotation of said engine.

17. Starting mechanism for an internal combustion engine comprising means to rotate the engine backwards from a stationary position to effect compression of air in a cylinder, the piston of which has passed the normal firing point during previous operation of the engine, ignition means, a distributor set at a greatly retarded position for the starting operation, means for injecting fuel into the cylinders of the engine, and mean for causing operation of said ignition mechanism through said distributor at said retarded position to again produce forward rotation of the engine.

18. Starting mechanism for an internal combustion engine comprising a starting lever operable upon being depressed to rotate the crank shaft of the engine backwards to effect compression of air in a cylinder that is on its firing stroke, an impulse magneto and a distributor for supplying ignition current to the spark plugs of said engine, said starting lever being operatively connected with said distributor to retard the same and compressed air in said cylinder is fired for starting the engine.

19. Starting mechanism for an internal combustion engine comprising a foot pedal operable upon being depressed to rotate the engine backwards to effect compression of air in a cylinder that is on its firing stroke, an impulse magneto and a distributor for supplying ignition current to the spark plugs of said engine, said foot pedal being operatively connected with said distributor to retard the same during the starting operation and with said impulse mechanism of said magneto to operate the same upon the return of said pedal to normal position, fuel injectors for the cylinders of said engine, said foot pedal being cperatively connected therewith to inject fuel into the cylinders of the engine whereby upon operation of said impulse mechanism of said magneto the mixture of fuel and compressed air in said cylinder is fired for starting the engine.

20. Starting mechanism for an internal combustion engine comprising a starting element operable upon movement in one direction to rotate the crank shaft of the engine backwards to effect compression of air in a cylinder that is on its firing stroke, ignition mechanism including a distributor for supplying ignition current to the spark plugs of said engine, said starting element being operatively connected with said distributor to retard the same during the starting operation and with said magneto to operate the same upon the return of said starting element to normal position, fuel injectors for the cylinders of said engine, said starting element being operatively connected therewith to operate said injectors whereby upon operation of said magneto the mixture of fuel and compressed air in said cylinder is fired for starting the engine.

MARSHALL L. LOCKHART. 

